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Topic: stepper motor not working

I have put everything together and got everything working apart from the stepper motor it's just not turning. I watched the video several times and I believe i have all the wiring correct. It would be great if someone could post pictures of all the connections so people could check. Also has anyone else had any issues with the stepper motor. When I press the rotate on the web interface I get nothing. I'm in the UK and was wondering it anyone knows a site and model number I need to purchase a replacement if this one is faulty.

Thanks in advance for any advice you can offer

All the best

Col

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Re: stepper motor not working

You might have a hard time getting people to disassemble their scanners just so they can take pictures.

BUt I think I got a good shot of what you need.   Usually, stepper motors don't go bad, If, after you check your wiring, you still can't get the motor to work, I would check the the rest of the wiring, and then I would suspect the stepper driver.  I would pay attention to it because it can be fried pretty easy if you plug wires in wrong.

You should also check the ribbon cable that goes from the stepper assembly to the Pi.  Make sure pin1 points toward the turntable.  If that was plugged in wrong and powered up, that might be what toasted the stepper driver.

http://www.soliforum.com/misc.php?action=pun_attachment&item=8983

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To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

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Re: stepper motor not working

Thanks for your help that image is very useful. It looks like I have the wiring correct but I did have some issues at the start so I'm worried that I may have toasted the stepper driver. I so are these parts easy to replace.

It may just be me but I find it harder to follow a video and think it would be great to have these backed up with some close shoots of the finished connections. Unless these are already out there and I missed them.

Again thanks for taking the time to reply and adding the supporting image. I'm just going to recheck everything and is it looks OK go about getting a replacement.

Thanks

Col

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Re: stepper motor not working

Colin, when you first turn the scanner on, is there a lot of resistance to slowly turning the table by hand?  Does it get real easy to turn once the camera's light comes on?

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Re: stepper motor not working

Yes that is what happens.


No power motor easy to turn
Power up. I get a faint thud and then I can't turn it by hand. I'm sure I can here a hum
Camera comes on I can turn it again

Thanks for posting a reply.

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Re: stepper motor not working

This suggests that the stepper driver is receiving the enable motor and disable motor commands successfully.  At any point did you change any of the values on the Setup page of the software?  Also, have you detached or reattached motor wires while the unit was powered on (don't do this)?

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Re: stepper motor not working

No I've not changed the values on the setup page. Also I've never attached the wires whilst powered up. Does it sound like the motor is fired.

Thanks for your help

Col

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Re: stepper motor not working

It's unlikely that anything is wrong with the motor.  It's more likely that something happened to the stepper driver or that the step command is not reaching it.  Can you check for continuity in the ribbon cable wires using your multimeter?

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Re: stepper motor not working

Sorry I'm really new to all this, I have a multimeter but I've not used it before. I purchased one as someone said I needed it to check the issues I'm having with the scanner. Is it easy to check if not I could ask someone at work to maybe look at it as they may have a bit more experience. I would love to do it myself as you have to start somewhere.

I really appreciate all the help

Col

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Re: stepper motor not working

Colin,

You would stick a piece of bare wire in the matching hole for each side of the cable and then check for resistance (ohms).  The pages below describe the process in a little more detail.

http://www.instructables.com/id/Turn-an … nnections/
http://www.techrepublic.com/article/tro … ultimeter/

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Re: stepper motor not working

Thanks for your help. Looks like this is going to get a bit complicated for me I have to wait until I show my friend  but they are away for the next couple of weeks.

Sorry this is a bit of a newbie questions but what end of the cable do I unplug for testing. and am I testing against the pins that I connected the cable from.

Also Am I just checking for power I'm wondering how I can check the stepper motor is at fault rather than the command not reaching it.

Again thanks for you help. It's just strange that it can't be turned when the camera light comes on but is easy to turn all other times.

Thanks for your help

Col

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Re: stepper motor not working

It's look that your stepper is somewhat powered.
When powered, without no movement, stepper held his position.
Without power, stepper could-be turn freely by hand.

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Re: stepper motor not working

Hello, Colin.

In case it helps: read the e-mail at 2015-08-02 10:34:07 above carefully again.  They're not suggesting that you test the wires that go between the electronics and the stepper motor.  They're suggesting a continuity check of the stepper driver connection through the ribbon cable.  (So, maybe there's something wrong with the ribbon cable.)  The stepper driver is the little white pcb shown in the picture above.  So for each pin in the ribbon cable, test that there's continuity through the cable.

(Make sure the power's off when you do your check.)

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Re: stepper motor not working

Thanks for the feedback

I'm really new to all this and want to make sure I don't break anything. I have a bit more time next week to read everything you sent in the links. I hope it is the ribbon cablle it does have a small kink in it. If you could please tell me what cable I should purchase to replace it I can order this below I start, as I sure it is the cheapest part to replace. I'm in the UK so any purchase links here would be great.

Again thanks for everyoness help

Col

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Re: stepper motor not working

hi Colin.S,
Been some time since your posting, so hope this now resolved? 

As others may land here with same issue, perhaps I can advise them to check my posting regarding incorrect logic levels between Pi and the Stepper driver, as this can create similar symptoms to those you experienced.  In particular,  your observation that "It's just strange that it can't be turned when the camera light comes on but is easy to turn all other times."  This is probably due to a slight drop in 5V voltage when the camera turns on.  This would then slightly improve the chances that the stepper driver will accept the logic level as correct.

Reprap Prusa x1 ,  Reprap G frame Prusa x1,  OpenBuilds OX CNC x1, FreeLss/Ciclops 3D scanner x1

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Re: stepper motor not working

Viseng - actually the ATLAS 3D Scanner uses the DRV8834, which supports 3.3v logic levels.